Four-wheel walking aid



FIG. 1 is a first perspective view of a four-wheel walking aid showingmy new design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a right side view thereof;

FIG. 7 is a top view thereof; and,

FIG. 8 is a bottom view thereof.

The broken lines showing is for the purpose of illustrating portions ofthe four-wheel walking aid that form no part of the claimed design.

CLAIM The ornamental design for a four-wheel walking aid, as shown anddescribed.